390 research outputs found

    Increased cytotoxicity of oxidized flame soot

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    AbstractCombustion–generated particles released into the atmosphere undergo reactions with oxidants, which can change the particles’ physiochemical characteristics. In this work, we compare the physical and chemical properties and cellular response of particles fresh from a flame with those oxidized by ozone and nitrogen dioxide. The reaction with ozone and nitrogen dioxide does not significantly modify the physical characteristics of the particles (primary particle size, fractal dimension, and surface area). However, oxidation affects the chemical characteristics of the particles, creating more oxygen and nitrogen containing functional groups, and increases their hydrophilicity. In addition, oxidized soot generates more reactive oxygen species, as measured by the dithiothreitol (DTT) assay. Furthermore, oxidized soot is 1.5 – 2 times more toxic than soot that was not reacted with ozone, but the inflammatory response, measured by interleukin–8 (IL–8) secretion, is unchanged. These results imply that combustion–generated particles released into the atmosphere will have an increased toxicity on or after high ozone days

    Comparison of adipose tissue derived genes in endogenous Cushing’s syndrome versus diet-induced obesity

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    Introduction: Dysregulation of adipokine secretion and action is a characteristic feature of obesity and a key clinical feature of Cushing’s syndrome (CS). We have investigated whether endogenous glucocorticoid excess influences adipose tissue-derived gene expression. Material and methods: mRNA expression of adipokines; adiponectin, resistin, tumour necrosis factor-a, interleukin-6 (IL-6), angiotensinogen (AGT), plasminogen activator inhibitor type 1, retinol binding protein 4, visfatin, and cystatin C was assessed by quantitative real-time RT-PCR in visceral adipose tissue removed during abdominal surgery of eight patients with CS, and six control patients. Results: We did not find any significant difference in the investigated genes; however, the almost significant overexpression of AGT and underexpression of IL-6 might be noteworthy (p = 0.06 in both cases). Conclusions: No significant differences were found in the expression of the investigated genes known as cardiometabolic risk factors. This indicates that there are no major differences between endogenous hypercortisolism or diet-induced obesity regarding the expression of adipokines involved in cardiometabolic disorders. However, the difference in AGT and IL-6 expression might be included in pathways affecting fat distribution in C

    Calibration of the response function of CsI(Tl) scintillators to intermediate-energy heavy ions

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    Abstract The response function of 2-cm-thick CsI(Tl) scintillators with photodiode readouts were studied by directly exposing the detectors to beams of heavy ions (2≤Z≤36) with energy up to 25 MeV/u. The dependence of the light output on the energy (E) as well as on the atomic number and the mass of the ion is analyzed and discussed, and a parameterization of the light output as a function of Z and E is proposed

    Nervous-system-specific carcinogenesis by ethylnitrosourea in the rat: molecular and cellular aspects

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    A lead in the search for cellular determinants favoring neoplastic transformation may be provided by the pronounced tissue specificity of the oncogenic effect of certain carcinogens which do not require enzymatic metabolic activation, i.e., in cases where this specificity cannot be due to tissue differences in the activity of enzymes involved in the formation of the ultimate reactants. A carcinogen that fulfills this condition is the ethylating agent N-ethyl-N-nitrosourea (EtNU). Alkylation of nucleic acid constituents by N-nitroso compounds in relation to mutagenesis and carcinogenesis has received considerable attention recently

    Rapid and sustained reduction of serum growth hormone and insulin-like growth factor-1 in patients with acromegaly receiving lanreotide Autogel® therapy: a randomized, placebo-controlled, multicenter study with a 52 week open extension

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    The study was designed to evaluate the long-term efficacy and safety of the 28-day prolonged-release Autogel formulation of the somatostatin analogue lanreotide (Lan-Autogel) in unselected patients with acromegaly. The study comprised four phases: washout; a double-blind comparison with placebo, at a single randomized dose (60, 90 or 120 mg) of Lan-Autogel; a single-blind, fixed-dose phase for four injections (placebo group was re-allocated to active treatment); and eight injections with doses tailored according to biochemical response. Serum samples were assessed for growth hormone (GH) and insulin-like growth factor-1 (IGF-1) levels, at weeks 4, 13, 14, 15, 16, 32 and 52. 108 patients were enrolled and 99 completed 52 weeks’ treatment. Four weeks after the first injection, serum GH levels decreased by >50% from baseline in 63% of patients receiving Lan-Autogel compared with 0% receiving placebo (P < 0.001). After four injections, 72% of patients had a >50% reduction in GH levels; 49% patients achieved GH levels ≤ 2.5 ng/ml; 54% had normalized IGF-1; and 38% achieved the combined criterion of GH level ≤ 2.5 ng/ml and normalized IGF-1. The corresponding proportions by week 52 were 82, 54, 59 and 43%, respectively. In patients not requiring dose escalation to 120 mg, 85% achieved biochemical control (combined criterion). Treatment was well tolerated by all patients. In conclusion, Lan-Autogel was effective in controlling GH and IGF-1 hypersecretion in patients with acromegaly and showed a rapid onset of action

    Characterization of a Novel Fibroblast Growth Factor 10 (Fgf10) Knock-In Mouse Line to Target Mesenchymal Progenitors during Embryonic Development

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    Fibroblast growth factor 10 (Fgf10) is a key regulator of diverse organogenetic programs during mouse development, particularly branching morphogenesis. Fgf10-null mice suffer from lung and limb agenesis as well as cecal and colonic atresia and are thus not viable. To date, the Mlcv1v-nLacZ-24 transgenic mouse strain (referred to as Fgf10LacZ), which carries a LacZ insertion 114 kb upstream of exon 1 of Fgf10 gene, has been the only strain to allow transient lineage tracing of Fgf10-positive cells. Here, we describe a novel Fgf10Cre-ERT2 knock-in line (Fgf10iCre) in which a Cre-ERT2-IRES-YFP cassette has been introduced in frame with the ATG of exon 1 of Fgf10 gene. Our studies show that Cre-ERT2 insertion disrupts Fgf10 function. However, administration of tamoxifen to Fgf10iCre; Tomatoflox double transgenic embryos or adult mice results in specific labeling of Fgf10-positive cells, which can be lineage-traced temporally and spatially. Moreover, we show that the Fgf10iCre line can be used for conditional gene inactivation in an inducible fashion during early developmental stages. We also provide evidence that transcription factors located in the first intron of Fgf10 gene are critical for maintaining Fgf10 expression over time. Thus, the Fgf10iCre line should serve as a powerful tool to explore the functions of Fgf10 in a controlled and stage-specific manner

    Global Policy Barriers and Enablers to Exercise and Physical Activity in Kidney Care

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    Objective: Impairment in physical function and physical performance leads to decreased independence and health-related quality of life in people living with chronic kidney disease and end-stage kidney disease. Physical activity and exercise in kidney care are not priorities in policy development. We aimed to identify global policy-related enablers, barriers, and strategies to increase exercise participation and physical activity behavior for people living with kidney disease. Design and Methods: Guided by the Behavior Change Wheel theoretical framework, 50 global renal exercise experts developed policy barriers and enablers to exercise program implementation and physical activity promotion in kidney care. The consensus process consisted of developing themes from renal experts from North America, South America, Continental Europe, United Kingdom, Asia, and Oceania. Strategies to address enablers and barriers were identified by the group, and consensus was achieved. Results: We found that policies addressing funding, service provision, legislation, regulations, guidelines, the environment, communication, and marketing are required to support people with kidney disease to be physically active, participate in exercise, and improve health-related quality of life. We provide a global perspective and highlight Japanese, Canadian, and other regional examples where policies have been developed to increase renal physical activity and rehabilitation. We present recommendations targeting multiple stakeholders including nephrologists, nurses, allied health clinicians, organizations providing renal care and education, and renal program funders. Conclusions: We strongly recommend the nephrology community and people living with kidney disease take action to change policy now, rather than idly waiting for indisputable clinical trial evidence that increasing physical activity, strength, fitness, and function improves the lives of people living with kidney disease

    Genomic analysis of microRNA time-course expression in liver of mice treated with genotoxic carcinogen N-ethyl-N-nitrosourea

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    <p>Abstract</p> <p>Background</p> <p>Dysregulated expression of microRNAs (miRNAs) has been previously observed in human cancer tissues and shown promise in defining tumor status. However, there is little information as to if or when expression changes of miRNAs occur in normal tissues after carcinogen exposure.</p> <p>Results</p> <p>To explore the possible time-course changes of miRNA expression induced by a carcinogen, we treated mice with one dose of 120 mg/kg <it>N</it>-ethyl-<it>N</it>-nitrosourea (ENU), a model genotoxic carcinogen, and vehicle control. The miRNA expression profiles were assessed in the mouse livers in a time-course design. miRNAs were isolated from the livers at days 1, 3, 7, 15, 30 and 120 after the treatment and their expression was determined using a miRNA PCR Array. Principal component analysis of the miRNA expression profiles showed that miRNA expression at post-treatment days (PTDs) 7 and 15 were different from those at the other time points and the control. The number of differentially expressed miRNAs (DEMs) changed over time (3, 5, 14, 32, 5 and 5 at PTDs 1, 3, 7, 15, 30 and 120, respectively). The magnitude of the expression change varied with time with the highest changes at PTDs 7 or 15 for most of the DEMs. In silico functional analysis of the DEMs at PTDs 7 and 15 indicated that the major functions of these ENU-induced DEMs were associated with DNA damage, DNA repair, apoptosis and other processes related to carcinogenesis.</p> <p>Conclusion</p> <p>Our results showed that many miRNAs changed their expression to respond the exposure of the genotoxic carcinogen ENU and the number and magnitude of the changes were highest at PTDs 7 to 15. Thus, one to two weeks after the exposure is the best time for miRNA expression sampling.</p

    Acatalasemic mice are mildly susceptible to adriamycin nephropathy and exhibit increased albuminuria and glomerulosclerosis

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    Background: Catalase is an important antioxidant enzyme that regulates the level of intracellular hydrogen peroxide and hydroxyl radicals. The effects of catalase deficiency on albuminuria and progressive glomerulosclerosis have not yet been fully elucidated. The adriamycin (ADR) nephropathy model is considered to be an experimental model of focal segmental glomerulosclerosis. A functional catalase deficiency was hypothesized to exacerbate albuminuria and the progression of glomerulosclerosis in this model. Methods: ADR was intravenously administered to both homozygous acatalasemic mutant mice (C3H/AnLCs(b)Cs(b)) and control wild-type mice (C3H/AnLCs(a)Cs(a)). The functional and morphological alterations of the kidneys, including albuminuria, renal function, podocytic, glomerular and tubulointerstitial injuries, and the activities of catalase were then compared between the two groups up to 8 weeks after disease induction. Moreover, the presence of a mutation of the toll-like receptor 4 (tlr4) gene, which was previously reported in the C3H/HeJ strain, was investigated in both groups. Results: The ADR-treated mice developed significant albuminuria and glomerulosclerosis, and the degree of these conditions in the ADR-treated acatalasemic mice was higher than that in the wild-type mice. ADR induced progressive renal fibrosis, renal atrophy and lipid peroxide accumulation only in the acatalasemic mice. In addition, the level of catalase activity was significantly lower in the kidneys of the acatalasemic mice than in the wild-type mice during the experimental period. The catalase activity increased after ADR injection in wild-type mice, but the acatalasemic mice did not have the ability to increase their catalase activity under oxidative stress. The C3H/AnL strain was found to be negative for the tlr4 gene mutation. Conclusions: These data indicate that catalase deficiency plays an important role in the progression of renal injury in the ADR nephropathy model

    The role of reactive oxygen species in apoptosis of the diabetic kidney

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    Increased levels of reactive oxygen species (ROS) by hyperglycemia can induce apoptosis of renal cells and diabetic nephropathy. The redox balance in the renal cell seems, therefore, of the utmost importance. ROS-mediated apoptosis may be further aggravated by an inadequate cytoprotective response against ROS. When there are insufficient cytoprotective and ROS scavenging molecules, ROS lead to considerable cellular damage and to a point of no return in apoptosis. Induction of cytoprotective proteins may prevent or attenuate apoptosis, renal cell injury, and finally diabetic nephropathy. Here, we discuss some mechanisms of apoptosis and several strategies that have been probed to ameliorate, or to prevent apoptosis in the diabetic kidney
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